Path of the Indomitable

A lone figure stands atop the hill, armor in tatters from countless blows and coated in blood both his own and his foes. Behind him, his allies turn and flee from the battlefield to regroup and rearm. Before him, the great tide of foes that have already driven so many of his friends and comrades into their early graves. He stands there, unbroken and undaunted, for he knows that should he not make this final stand, his allies will be overrun and decimated. He does not let fear take his heart, for he knows that he stands in sacrifice to a far greater cause. He knows that many lives will be saved in exchange for his heroism. He knows that he alone can make the difference. He is unafraid, for he knows that he shall not die this day.

The Indomitable Barbarian uses their Rage not as a blind, foamy-mouthed rampage but as a calm, clear focus. They channel the pain of their countless wounds into a cold blooded trance that allows them to push beyond normal limits. They do not feel pain, only solace in their duty. They will stand against the tide, they will dam the flood, and they will happily sacrifice themselves for their allies.

Unbroken

At 3rd level when you take this Path, you learn to gain strength through your wounds. When below 50% health, you become Unbroken. While under the effects of Unbroken, you deal double Rage damage and gain +10 to your movement speed.

Interception

At 6th level, you gain the ability to sacrifice yourself to protect your allies. When an enemy makes an attack against an allied creature within range, you can use your reaction to move up to your movement speed to intercept the attack, placing yourself between your enemy and their target. If the attacker is making a melee attack, you achieve this simply by placing yourself within their melee attack range. Once within range, you become the target of their attack. If their attack roll does not meet your AC, the attack misses. Regardless, you then become the target for any additional attacks they may make until the end of their turn.

Biting Wounds

At 10th level, you've learned from personal experience where getting hit hurts the most and can use this knowledge against your foes. While raging, your crit range with all attacks becomes 19. While Unbroken, your crit range becomes 18. You also gain immunity to any effect that would decrease your maximum health.

Insurmountable

At 14th level, pain becomes yet another step on the path to salvation and you shall bear the burden for those who cannot. You gain the effects of Unbroken when under 75% health. When below 50% health, you gain the effects of Insurmountable. While under Insurmountable, you gain all the benefits of Unbroken, deal an additional d6 damage with each attack, gain resistance to all damage, and gain the Martyrdom ability. This power is intoxicating, and you're harder to shake from your pain-infused enlightenment. While Insurmountable, you gain half healing from all sources.

Martyrdom
When Insurmountable, you can use a bonus action to force your enemies' attention onto you. Any hostile creatures of your choice within 60 ft. must make a Wisdom saving throw against DC 8 + your proficiency bonus + your Constitution modifier. On a failed save, they are compelled to attack you and only you. Opportunity attacks against affected enemies are made at disadvantage but make all attacks against creatures other than you with disadvantage.